Anyone know the source of an intermittant raw gas smell in my Pontiac Montana? on 2004 Pontiac Montana

Only smell gas when engine is running or right after shutoff. Pulled vacuum hose thinking it was fuel pressure regulator but couldn't detect gas. Doesn't happen every day. No hard start or drivability problems. No leaks detected on the floor but the gas smell seems stronger at the engine.

by in New Haven, IN on February 28, 2012
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3 answers 4 comments
ANSWER by , February 28, 2012
May not be a gas leak but a combination of 2 things. Poor combustion due to worn out spark plugs or a bad spark plug coil and an exhaust leak between the catalytic converter and the main exhaust manifolds. Have to check both to see if the flex pipe is bad or the spark plugs are as well. Exhaust has a much stronger gas smell before it goes through the catalytic converter.
COMMENT by , February 28, 2012
Thanks for the information. The spark plugs are new. Could be the coil. I will also check out the exhaust leak. I still don't understand why the problem is intermittant.
COMMENT by , May 08, 2013
Did you figure out the problem and find a fix? I've had my Montana in 3 times for this issue and they can't figure it out.
COMMENT by , June 26, 2013
We have been chasing this problem for the past couple years. this is our 3rd time in today - but in the previous 2 attempts - no improvement. It comes and goes, and like a gremlin, usually isn't smelling bad on the day I bring it in to the shop. With the intermittent nature of the problem, I wonder if it isn't due to some computer malfunction.
COMMENT by , December 03, 2013
MINE was the injector o-rings!! Read it on another forum, couldn't see fuel, smelt it on the D.Side, when the hood was open as well.
ANSWER by , July 26, 2014
Check your fuel pressure regulator. It will leak at the seam intermittently. That should cure your problem.
ANSWER by , July 24, 2015
Open gas lid and watch to see if u see gas fumes. My gas leak was from gas cap and the neck or hose that comes from tank the gas cap hooks on to. I had to replace both to fix mine.